#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <regex>
#include <sys/stat.h>
#include "../server.hpp"

#define DEFAULT_TIMEOUT 10

std::unordered_map<int, std::string> _statu_msg =
{
    {100,  "Continue"},
    {101,  "Switching Protocol"},
    {102,  "Processing"},
    {103,  "Early Hints"},
    {200,  "OK"},
    {201,  "Created"},
    {202,  "Accepted"},
    {203,  "Non-Authoritative Information"},
    {204,  "No Content"},
    {205,  "Reset Content"},
    {206,  "Partial Content"},
    {207,  "Multi-Status"},
    {208,  "Already Reported"},
    {226,  "IM Used"},
    {300,  "Multiple Choice"},
    {301,  "Moved Permanently"},
    {302,  "Found"},
    {303,  "See Other"},
    {304,  "Not Modified"},
    {305,  "Use Proxy"},
    {306,  "unused"},
    {307,  "Temporary Redirect"},
    {308,  "Permanent Redirect"},
    {400,  "Bad Request"},
    {401,  "Unauthorized"},
    {402,  "Payment Required"},
    {403,  "Forbidden"},
    {404,  "Not Found"},
    {405,  "Method Not Allowed"},
    {406,  "Not Acceptable"},
    {407,  "Proxy Authentication Required"},
    {408,  "Request Timeout"},
    {409,  "Conflict"},
    {410,  "Gone"},
    {411,  "Length Required"},
    {412,  "Precondition Failed"},
    {413,  "Payload Too Large"},
    {414,  "URI Too Long"},
    {415,  "Unsupported Media Type"},
    {416,  "Range Not Satisfiable"},
    {417,  "Expectation Failed"},
    {418,  "I'm a teapot"},
    {421,  "Misdirected Request"},
    {422,  "Unprocessable Entity"},
    {423,  "Locked"},
    {424,  "Failed Dependency"},
    {425,  "Too Early"},
    {426,  "Upgrade Required"},
    {428,  "Precondition Required"},
    {429,  "Too Many Requests"},
    {431,  "Request Header Fields Too Large"},
    {451,  "Unavailable For Legal Reasons"},
    {501,  "Not Implemented"},
    {502,  "Bad Gateway"},
    {503,  "Service Unavailable"},
    {504,  "Gateway Timeout"},
    {505,  "HTTP Version Not Supported"},
    {506,  "Variant Also Negotiates"},
    {507,  "Insufficient Storage"},
    {508,  "Loop Detected"},
    {510,  "Not Extended"},
    {511,  "Network Authentication Required"}
};

std::unordered_map<std::string,std::string> _mime_msg = 
{
    {".aac",        "audio/aac"},
    {".abw",        "application/x-abiword"},
    {".arc",        "application/x-freearc"},
    {".avi",        "video/x-msvideo"},
    {".azw",        "application/vnd.amazon.ebook"},
    {".bin",        "application/octet-stream"},
    {".bmp",        "image/bmp"},
    {".bz",         "application/x-bzip"},
    {".bz2",        "application/x-bzip2"},
    {".csh",        "application/x-csh"},
    {".css",        "text/css"},
    {".csv",        "text/csv"},
    {".doc",        "application/msword"},
    {".docx",       "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
    {".eot",        "application/vnd.ms-fontobject"},
    {".epub",       "application/epub+zip"},
    {".gif",        "image/gif"},
    {".htm",        "text/html"},
    {".html",       "text/html"},
    {".ico",        "image/vnd.microsoft.icon"},
    {".ics",        "text/calendar"},
    {".jar",        "application/java-archive"},
    {".jpeg",       "image/jpeg"},
    {".jpg",        "image/jpeg"},
    {".js",         "text/javascript"},
    {".json",       "application/json"},
    {".jsonld",     "application/ld+json"},
    {".mid",        "audio/midi"},
    {".midi",       "audio/x-midi"},
    {".mjs",        "text/javascript"},
    {".mp3",        "audio/mpeg"},
    {".mpeg",       "video/mpeg"},
    {".mpkg",       "application/vnd.apple.installer+xml"},
    {".odp",        "application/vnd.oasis.opendocument.presentation"},
    {".ods",        "application/vnd.oasis.opendocument.spreadsheet"},
    {".odt",        "application/vnd.oasis.opendocument.text"},
    {".oga",        "audio/ogg"},
    {".ogv",        "video/ogg"},
    {".ogx",        "application/ogg"},
    {".otf",        "font/otf"},
    {".png",        "image/png"},
    {".pdf",        "application/pdf"},
    {".ppt",        "application/vnd.ms-powerpoint"},
    {".pptx",       "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
    {".rar",        "application/x-rar-compressed"},
    {".rtf",        "application/rtf"},
    {".sh",         "application/x-sh"},
    {".svg",        "image/svg+xml"},
    {".swf",        "application/x-shockwave-flash"},
    {".tar",        "application/x-tar"},
    {".tif",        "image/tiff"},
    {".tiff",       "image/tiff"},
    {".ttf",        "font/ttf"},
    {".txt",        "text/plain"},
    {".vsd",        "application/vnd.visio"},
    {".wav",        "audio/wav"},
    {".weba",       "audio/webm"},
    {".webm",       "video/webm"},
    {".webp",       "image/webp"},
    {".woff",       "font/woff"},
    {".woff2",      "font/woff2"},
    {".xhtml",      "application/xhtml+xml"},
    {".xls",        "application/vnd.ms-excel"},
    {".xlsx",       "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
    {".xml",        "application/xml"},
    {".xul",        "application/vnd.mozilla.xul+xml"},
    {".zip",        "application/zip"},
    {".3gp",        "video/3gpp"},
    {".3g2",        "video/3gpp2"},
    {".7z",         "application/x-7z-compressed"}
};

class Util
{
    public:
        //字符串分割
        static size_t Split(const std::string &src,const std::string &sep,std::vector<std::string> *arr)
        {
            size_t offset = 0;
            //有10个字符，offset是查找的起始位置，范围应该是0~9，offset==10就代表已经越界了
            while (offset < src.size())
            {
                /* 在src字符串偏移量offset处，开始向后查找sep字符/子串，返回查找到的位置 */
                size_t pos = src.find(sep, offset);
                if(pos == std::string::npos)
                {
                    //将剩余的部分当作一个子串，放入arry中
                    arr->push_back(src.substr(offset));
                    return arr->size();
                }
                //连续的分隔符直接跳过
                if(pos == offset)
                {
                    offset = pos + sep.size();
                    continue;
                }
                arr->push_back(src.substr(offset, pos - offset));
                offset = pos + sep.size();
            }
            return arr->size();
        }
        //读取文件内容
        static bool ReadFile(const std::string &filename, std::string *buf)
        {
            std::ifstream ifs(filename, std::ios::binary);
            if(ifs.is_open() == false)
            {
                ERR_LOG("OPEN %s FILE FAILED",filename.c_str());
                return false;
            }
            size_t fsize = 0;
            //跳转读写位置到末尾，偏移量为0
            ifs.seekg(0, ifs.end);
            //获取当前读写位置相对于起始位置的偏移量，从末尾偏移刚好就是文件大小
            fsize = ifs.tellg();
            //跳转到起始位置
            ifs.seekg(0,ifs.beg);
            buf->resize(fsize);//开辟文件大小的空间
            ifs.read(&(*buf)[0],fsize);
            if(ifs.good() == false)
            {
                ERR_LOG("READ %s FILE FAILED!!",filename.c_str());
                ifs.close();
                return false;
            }
            ifs.close();
            return true;
        }
        //向文件写入数据
        static bool WriteFile(const std::string &filename, const std::string &buf)
        {
            std::ofstream ofs(filename, std::ios::binary | std::ios::trunc);
            if(ofs.is_open() == false)
            {
                ERR_LOG("OPEN %s FILE FAILED!",filename.c_str());
                return false;
            }
            ofs.write(buf.c_str(),buf.size());
            if(ofs.good() == false)
            {
                ERR_LOG("WRITE %s FILE FAILED!",filename.c_str());
                ofs.close();
                return false;
            }
            ofs.close();
            return true;
        }
        //URL编码,编码URL中资源路径与查询字符串中的特殊字符与HTTP请求中特殊字符产生歧义
        //编码格式：将特殊字符的ascii值，转换为两个16进制字符，再加上前缀%      C++ ->C%2B2B
        //不编码的特殊字符：  RFC3986文档规定 . - _ ~ 字母 数字均属于绝对不编码字符
        //RFC3986文档规定，编码格式 %HH
        //W3C标准中规定，查询字符串中的空格，需要编码为+，解码则是+转空格
        static std::string UrlEncode(const std::string url,bool convert_space_to_plus)
        {
            std::string res;
            for(auto &c : url)
            {
                if(c == '.' || c == '-' || c == '~' || c == '_' || isalnum(c))
                {
                    res += c;
                    continue;
                }
                if(c == ' ' && convert_space_to_plus == true)
                {
                    res += '+';
                    continue;
                }
                //剩下的情况字符都是需要编码成为 %HH 格式
                char tmp[4] = {0};
                snprintf(tmp, 4, "%%%02x",c);
                res += tmp;
            }
            return res;
        }
        //16进制字符转整型  a->10 A->10
        static char HEXTOI(char c)
        {
            if(c >= '0' && c <= '9')
            {
                return c - '0';
            }
            else if(c >= 'a' && c <= 'z')
            {
                return c - 'a' + 10;
            }
            else if(c >= 'A' && c<= 'Z')
            {
                return c - 'A' + 10;
            }
            return -1;
        }
        //URL解码
        static std::string UrlDecode(const std::string url, bool convert_plus_to_space )
        {
            //遇到了%，则将紧随其后的2个字符。转换为数字，第一个数字左移4位（×16），然后加上第二个数字
            std::string res;
            for(int i = 0; i < url.size(); i++)
            {
                if(url[i] == '+' && convert_plus_to_space == true)
                {
                    res += ' ';
                    continue;
                }
                if(url[i] == '%' && (i + 2) < url.size())
                {
                    char v1 = HEXTOI(url[i+1]);
                    char v2 = HEXTOI(url[i+2]);
                    char v = v1 * 16 + v2;
                    res += v;
                    i += 2;
                    continue;
                }
                res += url[i];
            }
            return res;
        }
        //响应状态码的描述信息获取
        static std::string StatuDesc(int statu)
        {
            auto it = _statu_msg.find(statu);
            if(it != _statu_msg.end())
            {
                return it->second;
            }
            return "Unknow";
        }
        //根据文件后缀名获取文件mime
        static std::string ExtMime(const std::string &filename)
        {   
            // a.b.txt 先获取文件扩展名
            size_t pos = filename.find_last_of('.');
            if(pos == std::string::npos)
            {
                return "application/octet-stream";
            }
            //根据扩展名，获取mime
            std::string ext = filename.substr(pos);
            auto it = _mime_msg.find(ext);
            if(it == _mime_msg.end())
            {
                return "application/octet-stream";
            }
            return it->second;
        }
        //判断一个文件是否是一个目录
        static bool IsDirectory(const std::string &filename)
        {
            struct stat st;
            int ret = stat(filename.c_str(), &st);//获取文件信息，并存储再stat st中
            if(ret < 0)
            {
                return false;
            }
            return S_ISDIR(st.st_mode);
        }
        //判断一个文件是否是一个普通文件
        static bool IsRegular(const std::string &filename)
        {
            struct stat st;
            int ret = stat(filename.c_str(), &st);//获取文件信息，并存储再stat st中
            if(ret < 0)
            {
                return false;
            }
            return S_ISREG(st.st_mode);
        }
        //http请求的资源路径有效性判断
        // /../login,这个路径中的..会让路径的查找跑到相对根目录之外，这是不被允许的
        static bool ValidPath(const std::string &path)
        {
            //思想：按照/进行路径分割，根据有多少子目录，计算目录深度，有多少层，深度不能小于0
            std::vector<std::string> subdir;
            Split(path, "/", &subdir);
            int level = 0;
            for(auto &dir : subdir)
            {
                if(dir == "..")
                {
                    level--;//任意一层走出相对根目录，就认为有问题
                    if(level < 0)
                        return false;
                    continue;
                }
                level++;
            }
            return true;
        }
};

class HttpRequest
{
    public:
        std::string _method;   //请求方法
        std::string _path;     //资源路径
        std::string _version;  //协议版本
        std::string _body;     //请求正文
        std::smatch _matches;  //资源路径的正则提取数据
        std::unordered_map<std::string, std::string> _headers; //头部字段
        std::unordered_map<std::string, std::string> _params;  //查询字符串
    public:
        HttpRequest():_version("HTTP/1.1") {}
        //重置，上下文请求处理完成后，需要对请求内容进行重置
        void ReSet() 
        {
            _method.clear();
            _path.clear();
            _version = "HTTP/1.1";
            _body.clear();
            std::smatch match;
            _matches.swap(match);
            _headers.clear();
            _params.clear();
        }
        //插入头部字段
        void SetHeader(const std::string &key, const std::string &val)
        {
            _headers.insert(std::make_pair(key, val));
        }
        //判断是否存在指定头部字段
        bool HasHeader(const std::string &key) const
        {
            auto it = _headers.find(key);
            if(it == _headers.end())
            {
                return false;
            }
            return true;
        }
        //获取指定头部字段的值
        std::string GetHeader(const std::string &key) const
        {
            auto it = _headers.find(key);
            if(it == _headers.end())
            {
                return "";
            }
            return it->second;
        }
        //插入查询字符串
        void SetParam(const std::string &key, const std::string &val)
        {
            _params.insert(std::make_pair(key, val));
        }
        //判断是否有某个指定的查询字符串
        bool HasParam(const std::string &key) const
        {
            auto it = _params.find(key);
            if(it == _params.end())
            {
                return false;
            }
            return true;
        }
        //获取指定的查询字符串
        std::string GetParam(const std::string &key) const
        {
            auto it = _params.find(key);
            if(it == _params.end())
            {
                return "";
            }
            return it->second;
        }
        //获取正文长度
        size_t ContentLength() const
        {
            bool ret = HasHeader("Content-Lenth");
            if(ret == false)
            {
                return 0;
            }
            std::string clen = GetHeader("Content-Lenth");
            return std::stol(clen);
        }
        //判断是否是短连接
        bool Close() const
        {
            if(HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive")
            {
                return false;
            }
            return true;
        }
};

class HttpResponse
{
    public:
        int _statu;
        bool _redirect_flag;
        std::string _body;
        std::string _redirect_url;
        std::unordered_map<std::string, std::string> _headers;
    public:
        HttpResponse():_statu(200),_redirect_flag(false){}
        HttpResponse(int statu):_statu(statu),_redirect_flag(false){}
        void ReSet()
        {
            _statu = 200;
            _redirect_flag = false;
            _body.clear();
            _redirect_url.clear();
            _headers.clear();
        }
        //插入头部字段
        void SetHeader(const std::string &key, const std::string &val)
        {
            _headers.insert(std::make_pair(key, val));
        }
        //判断是否存在指定头部字段
        bool HasHeader(const std::string &key)
        {
            auto it = _headers.find(key);
            if(it == _headers.end())
            {
                return false;
            }
            return true;
        }
        //获取指定头部字段的值
        std::string GetHeader(const std::string &key)
        {
            auto it = _headers.find(key);
            if(it == _headers.end())
            {
                return "";
            }
            return it->second;
        }
        void SetContent(const std::string &body, const std::string &type = "text/html")
        {
            _body = body;
            SetHeader("Content-Type", type);
        }
        //设置重定向
        void SetRedirect(const std::string &url, int statu = 302)
        {
            _statu = statu;
            _redirect_flag = true;
            _redirect_url = url;
        }
        //判断是否是短连接
        bool Close()
        {
            if(HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive")
            {
                return false;
            }
            return true;
        }
};

typedef enum 
{
    RECV_HTTP_ERROR,
    RECV_HTTP_LINE,
    RECV_HTTP_HEAD,
    RECV_HTTP_BODY,
    RECV_HTTP_OVER
}HttpRecvStatu;

#define MAX_LINE 8192

class HttpContext
{
    private:
        int _resp_statu; //响应状态码
        HttpRecvStatu _recv_statu; //当前接收及解析的阶段状态
        HttpRequest _request;  //已经解析得到的请求信息
    private:
        bool ParseHttpLine(const std::string &line)
        {
            std::smatch matches;
            std::regex e("(GET|HEAD|POST|PUT|DEDETE) ([^?]*)(?:\\?(.*))? (HTTP/1\\.[01])(?:\n|\r\n)?",std::regex::icase);
            bool ret = std::regex_match(line, matches, e);
            if(ret == false)
            {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 400; //BAD REQUEST
                return false;
            }
            //请求方法的获取
            _request._method = matches[1];
            std::transform(_request._method.begin(), _request._method.end(),_request._method.begin(), ::toupper);//参数分别为迭代器起点，终点，结果放在哪，要进行的操作
            //资源路径的获取，需要进行URL解码操作，但是不需要+转空格
            _request._path = Util::UrlDecode(matches[2],false);
            //协议版本的获取
            _request._version = matches[4];
            //查询字符串的获取与处理
            std::vector<std::string> query_string_arry;
            std::string query_string = matches[3];
            //查询字符串的格式 key=val&key=val...,先以 & 符号进行分割，得到各个子串
            Util::Split(query_string,"&",&query_string_arry);
            //针对各个子串，以 = 符号进行分割，得到key 和val，得到之后需要进行URL解码
            for(auto &str : query_string_arry)
            {
                size_t pos = str.find("=");
                if(pos == std::string::npos)
                {
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 400;//BAD REQUEST
                    return false;
                }
                std::string key = Util::UrlDecode(str.substr(0,pos),true);
                std::string val = Util::UrlDecode(str.substr(pos+1),true);
                _request.SetParam(key, val);
            }
            return true;
        }

        bool RecvHttpLine(Buffer *buf)
        {
            if(_recv_statu != RECV_HTTP_LINE) return false; 
            //1.获取一行数据，带有末尾的换行
            std::string line = buf->GetLineAndPop();
            //2.缓冲区中的数据不足一行，则需要判断缓冲区的可读数据长度，如果很长了都不足一行，这是有问题的
            if(line.size() == 0)
            {
                if(buf->ReadAbleSize() > MAX_LINE)
                {
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414; //URI TOO LONG
                    return false;
                }
                //缓冲区中数据不足一行，但是也不多，就等等新数据的到来
                return true;
            }
            if(line.size() > MAX_LINE)
            {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414;//URI TOO LONG
                return false;
            }
            bool ret = ParseHttpLine(line);
            if(ret == false)
            {
                return false;
            }
            //首行处理完毕，进入头部获取阶段
            _recv_statu = RECV_HTTP_HEAD;
            return true;
        }
        bool RecvHttpHead(Buffer *buf)
        {
            if(_recv_statu != RECV_HTTP_HEAD) return false;
            //一行一行取出数据，直到遇到空行为止，  头部的格式 key: val\r\nkey: val\r\n...
            while(1)
            {
                //1.获取一行数据
                std::string line = buf->GetLineAndPop();
                //2.缓冲区中的数据不足一行，则需要判断缓冲区的可读数据长度，如果很长了都不足一行，这是有问题的
                if(line.size() == 0)
                {
                    if(buf->ReadAbleSize() > MAX_LINE)
                    {
                        _recv_statu = RECV_HTTP_ERROR;
                        _resp_statu = 414; //URI TOO LONG
                        return false;
                    }
                    //缓冲区中数据不足一行，但是也不多，就等等新数据的到来
                    return true;
                }
                if(line.size() > MAX_LINE)
                {
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414;//URI TOO LONG
                    return false;
                }
                if(line == "\n" || line == "\r\n")
                {
                    break;
                }
                bool ret = ParseHttpHead(line);
                if(ret == false)
                {
                    return false;
                }
            }
            //头部处理完毕，进入头部获取阶段
            _recv_statu = RECV_HTTP_BODY;
            return true;
        }
        bool ParseHttpHead(std::string &line)
        {
            //key: val\r\nkey: \r\n...
            if(line.back() == '\n')  line.pop_back(); //末尾是换行则去掉换行字符
            if(line.back() == '\r')  line.pop_back(); //末尾是回车则去掉换行字符
            size_t pos = line.find(": ");
            if(pos == std::string::npos)
            {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 400;//
                return false;
            }
            std::string key = line.substr(0,pos);
            std::string val = line.substr(pos+2);
            _request.SetHeader(key, val);
            return true;
        }
        bool RecvHttpBody(Buffer *buf)
        {
            if(_recv_statu != RECV_HTTP_BODY) return false;
            //1.获取正文长度
            size_t content_length = _request.ContentLength();
            if(content_length == 0)
            {
                //没有正文，则请求接收解析完毕
                _recv_statu = RECV_HTTP_OVER;
                return true;
            }
            //2.当前已经接收了多少正文，其实就是往 _request._body 中放了多少数据了
            size_t real_len = content_length - _request._body.size();//实际还需要接收的正文长度
            //3.接收正文放到body中，但是也要考虑当前缓冲区中的数据，是否是全部的正文
            //  3.1 缓冲区中数据，包含了当前请求的所有正文，则取出所需的数据
            if(buf->ReadAbleSize() >= real_len)
            {
                _request._body.append(buf->ReadPos(),real_len);
                buf->MoveReadOffset(real_len);
                _recv_statu = RECV_HTTP_OVER;
                return true;
            }
            //  3.2 缓冲区中数据，无法满足当前正文的需要，数据不足，取出数据，然后等待新数据到来
            _request._body.append(buf->ReadPos(), buf->ReadAbleSize());
            buf->MoveReadOffset(buf->ReadAbleSize());
            return true; 
        }
    public:
        HttpContext():_resp_statu(200),_recv_statu(RECV_HTTP_LINE) {}
        void ReSet()
        {
            _resp_statu = 200;
            _recv_statu = RECV_HTTP_LINE;
            _request.ReSet();
        }
        int RespStatu()
        {
            return _resp_statu;
        }
        HttpRecvStatu RecvStatu()
        {
            return _recv_statu;
        }
        HttpRequest &Request()
        {
            return _request;
        }
        //接收并解析HTTP请求
        void RecvHttpRequest(Buffer *buf)
        {
            //不同的状态，做不同的事情，但是这里不要break，因为处理完请求行后，应该立即处理头部，而不是退出等新数据
            switch(_recv_statu)
            {
                case RECV_HTTP_LINE: RecvHttpLine(buf);
                case RECV_HTTP_HEAD: RecvHttpHead(buf);
                case RECV_HTTP_BODY: RecvHttpBody(buf);
            }
            return;
        }
};

class HttpServer
{
    private:
        using Handler = std::function<void(const HttpRequest &, HttpResponse *)>;
        using Handlers = std::vector<std::pair<std::regex, Handler>>;
        Handlers _get_route;
        Handlers _post_route;
        Handlers _put_route;
        Handlers _delete_route;
        std::string _basedir; //静态资源根目录
        TcpServer _server;
    private:
        void ErrorHandler(const HttpRequest &req, HttpResponse *rsp)
        {
            //1.组织一个错误展示页面
            std::string body;
            body += "<html>";
            body += "<head>";
            body += "<meta http-equiv='Content-Type' content='text/html;charset=utf-8'>";
            body += "</head>";
            body += "<body>";
            body += "<h1>";
            body += std::to_string(rsp->_statu);
            body += " ";
            body += Util::StatuDesc(rsp->_statu);
            body += "</h1>";
            body += "</body>";
            body += "</html>";
            //2.将页面数据，当作响应正文，放入rsp中
            rsp->SetContent(body, "text/html");
        }
        //将HttpResponse中的要素按照http协议格式进行组织，发送
        void WriteResponse(const PtrConnection &conn, const HttpRequest &req, HttpResponse &rsp)
        {
            //1.先完善头部字段
            if(req.Close() == true)
            {
                rsp.SetHeader("Connection", "close");
            }
            else
            {
                rsp.SetHeader("Connection", "keep-alive");
            }
            if(rsp._body.empty() == false && rsp.HasHeader("Content-Length") == false)
            {
                rsp.SetHeader("Content-Lenth", std::to_string(rsp._body.size()));
            }
            if(rsp._body.empty() == false && rsp.HasHeader("Content-Type") == false)
            {
                rsp.SetHeader("Content-Type", "application/octet-stream");
            }
            if(rsp._redirect_flag == true)
            {
                rsp.SetHeader("Location", rsp._redirect_url);
            }
            //2.将rsp中的要素，按照http协议格式进行组织
            std::stringstream rsp_str;
            rsp_str << req._version << " " << std::to_string(rsp._statu) << " " << Util::StatuDesc(rsp._statu) << "\r\n";
            for(auto &head : rsp._headers)
            {
                rsp_str << head.first << ": " << head.second << "\r\n";
            }
            rsp_str << "\r\n";
            rsp_str << rsp._body;
            //3.发送数据
            conn->Send(rsp_str.str().c_str(), rsp_str.str().size());
        }
        bool IsFileHandler(const HttpRequest &req)
        {
            //1.必须设置了静态资源根目录
            if(_basedir.empty())
            {
                return false;
            }
            //2.请求方法必须是GET / HEAD请求方法
            if(req._method != "GET" && req._method != "HEAD")
            {
                return false;
            }
            //3.请求的资源路径必须是一个合法路径
            if(Util::ValidPath(req._path) == false)
            {
                return false;
            }
            //4.请求的资源必须存在，且是一个普通文件
            //  有一种请求比较特殊---目录: /,/image/ ，这种情况给后面默认追加一个 index.html
            // index.html  /image/a.png
            // 不要忘了前缀的相对根目录，也就是将请求的路径转换为实际存在的路径 
            std::string req_path = _basedir + req._path;//为了避免直接修改请求的资源路径，因此定义一个临时对象
            if(req._path.back() == '/')
            {
                req_path += "index.html";
            }
            if(Util::IsRegular(req_path) == false)
            {
                return false;
            }
            return true;
        }

        //静态资源的请求处理 -- 将静态资源文件的数据读取出来，放到rsp的_body中，并设置mime
        void FileHandler(const HttpRequest &req, HttpResponse *rsp)
        {
            std::string req_path = _basedir + req._path;//为了避免直接修改请求的资源路径，因此定义一个临时对象
            if(req._path.back() == '/')
            {
                req_path += "index.html";
            }
            bool ret = Util::ReadFile(req_path,&rsp->_body);
            if(ret == false)
            {
                return;
            }
            std::string mime = Util::ExtMime(req_path);
            rsp->SetHeader("Content-Type", mime);
            return;
        }
        //
        void Dispatcher(HttpRequest &req, HttpResponse *rsp, Handlers &handlers)
        {
            //在对应请求方法的路由表中，查找是否含有对应资源请求的处理函数，有则调用，没有则返回404
            //思想： 路由表存储的是键值对 --正则表达式 & 处理函数
            //使用正则表达式，对请求的资源路径进行正则匹配，匹配成功就使用对应函数进行处理
            //  /numbers/(d+)     /numbers/12345
            for (auto &handler : handlers)
            {
                const std::regex &re = handler.first;
                const Handler &functor = handler.second;
                bool ret = std::regex_match(req._path, req._matches,re);
                if(ret == false)
                {
                    continue;
                }
                return functor(req,rsp);//传入请求信息，和空的rsp，执行处理函数
            }
            rsp->_statu = 404;
        }
        void Route(HttpRequest &req, HttpResponse *rsp)
        {
            //1.对请求进行分辨，是一个静态资源请求，还是一个功能性请求
            //  静态资源请求，则进行静态资源的处理
            //  功能性请求，则需要通过几个请求路由表来确定是否有处理函数
            //  既不是静态资源请求，也没有设置对应的功能性请求处理函数，就返回方法不被允许
            if(IsFileHandler(req) == true)
            {
                //是一个静态资源请求，则返回静态资源请求的处理
                return FileHandler(req, rsp);
            }
            if(req._method == "GET" || req._method == "HEAD")
            {
                return Dispatcher(req, rsp, _get_route);
            }
            else if(req._method == "POST")
            {
                return Dispatcher(req, rsp, _post_route);
            }
            else if(req._method == "PUT")
            {
                return Dispatcher(req, rsp, _put_route);
            }
            else if(req._method == "DELETE")
            {
                return Dispatcher(req, rsp, _delete_route);
            }
            rsp->_statu = 405; //Method Not Allowed
            return;
        }
        //设置上下文
        void OnConnected(const PtrConnection &conn)
        {
            conn->SetContext(HttpContext());
            DBG_LOG("NEW CONNECTION %p", conn.get());
        }
        void OnMessage(const PtrConnection &conn, Buffer *buffer)
        {
            while(buffer->ReadAbleSize() > 0)
            {
                //1.获取上下文
                HttpContext *context = conn->GetContext()->get<HttpContext>();
                //2.通过上下文对缓冲区数据进行解析，得到HttpRequest对象
                //   1.如果缓冲区的数据解析出错，就直接回复出错响应
                //   2.如果解析正常，且请求已经获取完毕，才开始取进行处理
                context->RecvHttpRequest(buffer);
                HttpRequest &req = context->Request();
                HttpResponse rsp(context->RespStatu());
                if(context->RespStatu() >= 400)
                {
                    //进行错误响应，关闭连接
                    ErrorHandler(req, &rsp);//填充一个错误显示页面数据到rsp中
                    WriteResponse(conn, req, rsp);//组织响应发送给客户端
                    context->ReSet();
                    buffer->MoveReadOffset(buffer->ReadAbleSize());//出错了就把缓冲区数据清空
                    conn->Shutdown();//关闭连接
                    return;
                }
                if(context->RecvStatu() != RECV_HTTP_OVER)
                {
                    //当前请求还没有接收完整，则退出，等新数据到来再重新继续处理
                    return;
                }
                //3.请求路由 + 业务处理
                Route(req, &rsp);
                //4.对HttpResponse进行组织发送
                WriteResponse(conn,req,rsp);
                //5.重置上下文
                context->ReSet();
                //6.根据长短连接判断是否关闭连接或者继续处理
                if(rsp.Close() == true) conn->Shutdown();//短连接则直接关闭
            }
            return;
        }
    public:
        HttpServer(int port, int timeout = DEFAULT_TIMEOUT):_server(port)
        {
            _server.EnableInactiveRelease(timeout);
            _server.SetConnectedCallback(std::bind(&HttpServer::OnConnected,this,std::placeholders::_1));
            _server.SetMessageCallback(std::bind(&HttpServer::OnMessage,this,std::placeholders::_1,std::placeholders::_2));
        }
        void SetBaseDir(const std::string &path)
        {
            assert(Util::IsDirectory(path) == true);
            _basedir = path;
        }
        //设置/添加，请求（请求的正则表达） 与处理函数的映射关系
        void Get(const std::string &pattern, const Handler &handler)
        {
             _get_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void Post(const std::string &pattern, const Handler &handler)
        {
             _post_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void Put(const std::string &pattern, const Handler &handler)
        {
             _put_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void Delete(const std::string &pattern, const Handler &handler)
        {
             _delete_route.push_back(std::make_pair(std::regex(pattern),handler));
        }
        void SetThreadCount(int count)
        {
            _server.SetThreadCount(count);
        }
        void Listen()
        {
            _server.Start();
        }
};